U.S. patent application number 11/120502 was filed with the patent office on 2006-01-05 for compounds for treatment of neurodegenerative diseases.
This patent application is currently assigned to EnVivo Pharmaceuticals, Inc.. Invention is credited to Christopher J. Cummings, David A. Lowe, William C. Ripka.
Application Number | 20060004041 11/120502 |
Document ID | / |
Family ID | 35320170 |
Filed Date | 2006-01-05 |
United States Patent
Application |
20060004041 |
Kind Code |
A1 |
Cummings; Christopher J. ;
et al. |
January 5, 2006 |
Compounds for treatment of neurodegenerative diseases
Abstract
The present invention relates to a class of small molecule
hydroxamic acid compounds capable of inhibiting histone
deacetylases (HDACs). The present invention also relates to methods
of preparation of hydroxamic acid HDAC inhibitor compounds of the
invention, which are N-substituted-1,2,3,4-tetrahydroisoquinoline
hydroxamic acid derivatives, and their incorporation into
pharmaceutical compositions and methods of administration. The
present invention also relates to
N-substituted-1,2,3,4-tetrahydroisoquinoline hydroxamic acid
derivatives, which may be prepared as a hydroxamic acid HDAC
inhibitor compound library that can be utilized in screening
methods known in the art.
Inventors: |
Cummings; Christopher J.;
(Brookline, MA) ; Lowe; David A.; (Park Ridge,
NJ) ; Ripka; William C.; (San Diego, CA) |
Correspondence
Address: |
PALMER & DODGE, LLP;KATHLEEN M. WILLIAMS
111 HUNTINGTON AVENUE
BOSTON
MA
02199
US
|
Assignee: |
EnVivo Pharmaceuticals,
Inc.
|
Family ID: |
35320170 |
Appl. No.: |
11/120502 |
Filed: |
May 3, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60567673 |
May 3, 2004 |
|
|
|
Current U.S.
Class: |
514/309 ;
514/310; 546/141; 546/146 |
Current CPC
Class: |
C07D 409/12 20130101;
C07D 217/08 20130101; C07D 401/10 20130101; A61K 31/47 20130101;
C07D 417/12 20130101; C07D 217/02 20130101; C07D 401/12 20130101;
C07D 401/06 20130101; C07D 217/06 20130101; C07D 471/04
20130101 |
Class at
Publication: |
514/309 ;
514/310; 546/141; 546/146 |
International
Class: |
A61K 31/4709 20060101
A61K031/4709; C07D 43/02 20060101 C07D043/02; C07D 41/02 20060101
C07D041/02 |
Claims
1. A hydroxamic acid compound represented by formula (I): ##STR11##
wherein: X is selected from the group consisting of a carbonyl
group (C.dbd.O), or a sulfonyl group (SO.sub.2); Y is selected from
the group consisting of C.sub.1-C.sub.6 alkyl,
R(R.sub.2)N--(CH.sub.2).sub.n--, ##STR12## ##STR13## wherein:
R.sub.1 and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; R.sub.1 and R.sub.2, taken together with the nitrogen
to which they are attached, form a heterocyclic ring, wherein said
heterocyclic ring is optionally substituted with a substituted or
unsubstituted lower alkyl group, or a substituted or unsubstituted
benzyl group; R.sub.3 and R.sub.4 are each independently selected
from the group consisting of hydrogen, halogen, straight chain
C.sub.1-C.sub.8 alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl, wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; R.sub.8 is hydrogen,
--(CH.sub.2).sub.nN(R.sub.1)(R.sub.2), or OR.sub.5, wherein
R.sub.1, R.sub.2 and R.sub.5 are as defined above; R.sub.9 is
hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; Z is --C(R.sub.3)-- or
nitrogen (N), wherein R3 is as defined above; and n is 0 to 6; or
hydrates, polymorphs, or pharmaceutically acceptable salts
thereof.
2. The hydroxamic acid compound of claim 1, represented by formula
(I): ##STR14## wherein: X is a carbonyl group (C.dbd.O); Y is
selected from the group consisting of
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR15## wherein: R.sub.1
and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; R.sub.1 and R.sub.2, taken together with the nitrogen
to which they are attached, form a heterocyclic ring, wherein said
heterocyclic ring is optionally substituted with a substituted or
unsubstituted lower alkyl group, or a substituted or unsubstituted
benzyl group; R.sub.3 and R.sub.4 are each independently selected
from the group consisting of hydrogen, halogen, straight chain
C.sub.1-C.sub.8 alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; Z is --C(R.sub.3)-- or nitrogen (N),
wherein R3 is as defined above; and n is 0 to 6; or hydrates,
polymorphs, or pharmaceutically acceptable salts thereof.
3. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-(4-guanidino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
4. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-(4-dimethylamino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
5. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-(quinoline-8-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
6. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-((4-dimethylamino-phenyl)-acetyl)-1,2,3,4-tetrahydro-isoquinoline-7-car-
boxylic acid hydroxyamide.
7. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-(4-dimethylamino-butyryl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
8. The hydroxamic acid compound of claim 1, wherein the hydroxamic
acid compound is
2-(4-imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
9. A process of preparing an hydroxamic acid compound represented
by formula (I): ##STR16## wherein: X is a carbonyl group (C.dbd.O);
Y is selected from the group consisting of C.sub.1-C.sub.6 alkyl,
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR17## ##STR18## wherein:
R.sub.1 and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; R.sub.1 and R.sub.2, taken together with the nitrogen
to which they are attached, form a heterocyclic ring, wherein said
heterocyclic ring is optionally substituted with a substituted or
unsubstituted lower alkyl group, or a substituted or unsubstituted
benzyl group; R.sub.3 and R.sub.4 are each independently selected
from the group consisting of hydrogen, halogen, straight chain
C.sub.1-C.sub.8 alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; R.sub.8 is hydrogen,
--(CH.sub.2).sub.nN(R.sub.1)(R.sub.2), or OR.sub.5, wherein
R.sub.1, R.sub.2 and R.sub.5 are as defined above; R.sub.9 is
hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; Z is --C(R.sub.3)-- or
nitrogen (N), wherein R3 is as defined above; and n is 0 to 6; or
hydrates, polymorphs, or pharmaceutically acceptable salts thereof,
comprising the steps of; reacting
1,2,3,4-tetrahydro-isoquinoline-7-carboxylic acid (Formula (II))
##STR19## with a polymeric resin to form a compound of formula
(III): ##STR20## wherein P is a polymeric resin; reacting the
compound of formula (III) with an acylating compound of formula
(IV): ##STR21## wherein W is a halogen, Cl, Br, or I, or with a
compound of formula (V): ##STR22## in the presence of a coupling
reagent, to form a compound of formula (VI): ##STR23## reacting the
compound of formula (VI) with (CH.sub.3).sub.2(OCH.sub.3)ONH.sub.2,
to form a compound of formula (VII): ##STR24## reacting the
compound of formula (VII) with pyridinium para-toluenesulfonate
(PPTS) to give the compound of Formula (I).
10. The process of claim 9, wherein said polymeric resin is
crosslinked.
11. The process of claim 9, wherein P is a polystyrene resin.
12. The process of claim 9, wherein said coupling reagent is
selected from the group consisting of
benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate
(PyBop), N,N'-carbonyldiimidazole,
1-cyclohexyl-3-3(2-morpholinomethyl)-carbodiimide,
N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide (EDC), and
dicyclohexylcarbodiimide (DCC).
13. The process of claim 9, wherein said coupling reagent is
benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate
(PyBop)
14. The process for preparing a hydroxamic acid compound of claim
9, wherein said hydroxamic acid compound is represented by formula
(I): ##STR25## wherein: X is a carbonyl group (C.dbd.O); Y is
selected from the group consisting of
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR26## wherein: R.sub.1
and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; R.sub.1 and R.sub.2, taken together with the nitrogen
to which they are attached, form a heterocyclic ring, wherein said
heterocyclic ring is optionally substituted with a substituted or
unsubstituted lower alkyl group, or a substituted or unsubstituted
benzyl group; R.sub.3 and R.sub.4 are each independently selected
from the group consisting of hydrogen, halogen, straight chain
C.sub.1-C.sub.8 alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(--NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl, wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; Z is --C(R.sub.3)-- or nitrogen (N),
wherein R3 is as defined above; and n is 0 to 6; or hydrates,
polymorphs, or pharmaceutically acceptable salts thereof.
15. The process of claim 9, wherein the hydroxamic acid compound is
2-(4-guanidino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
16. The process of claim 9, wherein the hydroxamic acid compound is
2-(4-dimethylamino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
17. The process of claim 9, wherein the hydroxamic acid compound is
2-(quinoline-8-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
18. The process of claim 9, wherein the hydroxamic acid compound is
2-((4-dimethylamino-phenyl)-acetyl)-1,2,3,4-tetrahydro-isoquinoline-7-car-
boxylic acid hydroxyamide.
19. The process of claim 9, wherein the hydroxamic acid compound is
2-(4-dimethylamino-butyryl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
20. The process of claim 9, wherein the hydroxamic acid compound is
2-(4-imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
21. A method of inhibiting HDAC comprising administering, in an
amount sufficient to cause inhibition, a hydroxamic acid compound
represented by formula (I): ##STR27## wherein: X is selected from
the group consisting of a carbonyl group (C.dbd.O), or a sulfonyl
group (SO.sub.2); Y is selected from the group consisting of
C.sub.1-C.sub.6 alkyl, R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--,
##STR28## ##STR29## wherein: R.sub.1 and R.sub.2 are each
independently selected from the group consisting of hydrogen,
straight chain lower alkyl, and branched lower alkyl; R.sub.1 and
R.sub.2, taken together with the nitrogen to which they are
attached, form a heterocyclic ring, wherein said heterocyclic ring
is optionally substituted with a substituted or unsubstituted lower
alkyl group, or a substituted or unsubstituted benzyl group;
R.sub.3 and R.sub.4 are each independently selected from the group
consisting of hydrogen, halogen, straight chain C.sub.1-C.sub.8
alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl, wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; R.sub.8 is hydrogen,
--(CH.sub.2).sub.nN(R.sub.1)(R.sub.2), or OR.sub.5, wherein
R.sub.1, R.sub.2 and R.sub.5 are as defined above; R.sub.9 is
hydrogen, C.sub.1--C.sub.8 alkyl, or benzyl; Z is --C(R.sub.3)-- or
nitrogen (N), wherein R3 is as defined above; and n is 0 to 6; or
hydrates, polymorphs, or pharmaceutically acceptable salts
thereof.
22. The method of claim 21, wherein the hydroxamic acid compound is
represented by formula (I): ##STR30## wherein: X is a carbonyl
group (C.dbd.O); Y is selected from the group consisting of
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR31## wherein: R.sub.1
and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; R.sub.1 and R.sub.2, taken together with the nitrogen
to which they are attached, form a heterocyclic ring, wherein said
heterocyclic ring is optionally substituted with a substituted or
unsubstituted lower alkyl group, or a substituted or unsubstituted
benzyl group; R.sub.3 and R.sub.4 are each independently selected
from the group consisting of hydrogen, halogen, straight chain
C.sub.1-C.sub.8 alkyl, (R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrolyl, wherein
R.sub.1 and R.sub.2 are as defined above; R.sub.5 is hydrogen,
C.sub.1-C.sub.8 alkyl, or benzyl; R.sub.6 is hydrogen, lower alkyl,
or benzyl; R.sub.7 is C.sub.1-C.sub.8 alkyl, benzylalkyl,
heteroalkyl or heteroaralkyl; Z is --C(R.sub.3)-- or nitrogen (N),
wherein R3 is as defined above; and n is 0 to 6; or hydrates,
polymorphs, or pharmaceutically acceptable salts thereof.
23. The method of claim 21, wherein the hydroxamic acid compound is
2-(4-guanidino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
24. The method of claim 21, wherein the hydroxamic acid compound is
2-(4-Dimethylamino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
25. The method of claim 21, wherein the hydroxamic acid compound is
2-(quinoline-8-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
26. The method of claim 21, wherein the hydroxamic acid compound is
2-((4-dimethylamino-phenyl)-acetyl)-1,2,3,4-tetrahydro-isoquinoline-7-car-
boxylic acid hydroxyamide.
27. The method of claim 21, wherein the hydroxamic acid compound is
2-(4-dimethylamino-butyryl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
28. The method of claim 21, wherein the hydroxamic acid compound is
2-(4-imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
29. A pharmaceutical composition comprising a therapeutically
effective amount of a hydroxamic acid compound of claim 1 in
admixture with a pharmaceutically acceptable carrier for oral or
parenteral administration.
30. The pharmaceutical composition of claim 29, wherein the
hydroxamic acid compound is selected from the group consisting of:
2-(4-guanidino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide;
2-(4-dimethylamino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide;
2-(quinoline-8-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide;
2-((4-dimethylamino-phenyl)-acetyl)-1,2,3,4-tetrahydro-isoquinoline-7-car-
boxylic acid hydroxyamide;
2-(4-dimethylamino-butyryl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide; and
2-(4-imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
31. A method of inhibiting HDAC comprising the oral or parenteral
administration of a pharmaceutical composition of claim 29.
32. A method of inhibiting HDAC comprising the oral or parenteral
administration of a pharmaceutical composition of claim 30.
33. A method of treating an HDAC mediated condition in a mammal
comprising the step of administering to said mammal, a
therapeutically effective amount of a hydroxamic acid compound of
claim 1.
34. The method of claim 33, wherein the HDAC mediated condition is
a neurodegenerative disease.
35. The method of claim 34 wherein the neurodegenerative disease is
a polyglutamine repeat disorder.
36. The method of claim 34 wherein the neurodegenerative disease is
Huntington's disease.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 60/567,673, filed on May 3, 2004, the contents
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Histone deacetylases (HDACs) are important zinc hydrolases
that are responsible for the regulation of gene expression through
deacetylation of the N-acetyl lysine residues of histone proteins
and other transcriptional regulators. HDACs are involved in
cell-cycle progression and differentiation. HDAC inhibitors, such
as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA),
have anti-tumor effects and can inhibit cell growth, induce
terminal termination, and prevent the formation of tumors in mice
models.
[0003] Evidence from recent studies suggest that transcriptional
dysregulation may contribute to the molecular pathogenesis of
Huntington's disease (HD). HD is an inherited, progressive
neurological disorder that is caused by a CAG/polyglutamine repeat
expansion for which there is currently no effective therapy. It has
been recently reported that administration of the potent histone
deacetylase inhibitor SAHA is effective against Huntington's
disease in a mouse model. Orally administered SAHA dramatically
improved the motor impairment in mice. HDAC inhibitors, therefore,
have the potential to be effective HD therapeutics.
[0004] The X-ray structure of an HDAC-like ortholog from the
thermophilic bacterium Aquifex aeolicus (Histone Deacetylase-Like
Protein (HDLP)-- sequence family 3.40.800.20.1-1C3P.pdb) is known.
For example, structures of a HDAC homologue bound to the TSA and
SAHA inhibitors, have been disclosed by Finnin et al., Science,
401, 188, (1999).
[0005] This HDAC-like protein shares a 35% identity with human
HDAC1 over 375 residues, deacetylates histones in vitro, and is
inhibited by TSA and SAHA. The structure shows an active site
containing a zinc-binding site and the residues making up the
active site and contact the inhibitors are conserved across the
known members of the HDAC family. The HDLP structure, therefore,
provides a structural rationale for the design of HDAC
inhibitors.
[0006] The currently known HDAC inhibitors in the art such as TSA
and SAHA may pose limitations with respect to their utility. For
example, the polyene chain present in TSA is potentially subject to
metabolism. Also, TSA is highly hydrophobic and may be
substantially protein bound. The corresponding saturated chain in
SAHA is expected to reduce affinity because of entropy
considerations in confining the flexible chain to a single
conformation when bound in the HDAC site.
SUMMARY OF THE INVENTION
[0007] The present invention concerns a new class of HDAC
inhibitors having the potential to function as therapeutics for
neurodegenerative diseases. In particular, the present invention
concerns hydroxamic acid compounds that are antagonists of histone
deacetylases (HDACs). In one aspect, the hydroxamic acid compounds
of the present invention are designed based on optional
structure-interaction modeling methods and screened in silico using
the histone deacetylase-like protein (HDLP) x-ray structures. The
compounds of the present invention, based on their HDAC inhibition
properties are, therefore, capable of providing therapeutic benefit
when administered to treat HDAC mediated symptoms such as those
found in neurodegenerative diseases including, for example,
polyglutamine repeat disorders such as Huntington's disease,
Spinocerebellar ataxias (e.g., types 1, 2, 3, 6, 7 and 17),
Machado-Joseph disease, Spinal and Bulbar muscular atrophy (SBMA or
Kennedy's disease), Dentatorubral Pallidoluysian Atrophy (DRPLA)
and other neurological conditions arising from polyglutamine
expansions, or disease arising from non-coding DNA repeat
expansions such as Fragile X syndrome, Fragile XE mental
retardation, Friedreich ataxia, myotonic dystrophy, Spinocerebellar
ataxias (types 8, 10 and 12) or other neurodegenerative diseases
such as spinal muscular atrophy (Werdnig-Hoffman disease,
Kugelberg-Welander disease), Alzheimer's disease, amyotrophic
lateral sclerosis, Parkinson's disease, Pick's disease, and
spongiform encephalopathies.
[0008] Additional neurodegenerative diseases for which HDAC
inhibitors can provide therapeutic benefit include, for example,
age-related memory impairment, agyrophilic grain dementia,
Parkinsonism-dementia complex of Guam, auto-immune conditions (eg
Guillain-Barre syndrome, Lupus), Biswanger's disease, brain and
spinal tumors (including neurofibromatosis), cerebral amyloid
angiopathies (Journal of Alzheimer's Disease vol 3, 65-73 (2001)),
cerebral palsy, chronic fatigue syndrome, corticobasal
degeneration, conditions due to developmental dysfunction of the
CNS parenchyma, conditions due to developmental dysfunction of the
cerebrovasculature, dementia--multi infarct, dementia--subcortical,
dementia with Lewy bodies, dementia of human immunodeficiency virus
(HIV), dementia lacking distinct histology, Dementia Pugilistica,
diffues neurofibrillary tangles with calcification, diseases of the
eye, ear and vestibular systems involving neurodegeneration
(including macular degeneration and glaucoma), Down's syndrome,
dyskinesias (Paroxysmal), dystonias, essential tremor, Fahr's
syndrome, fronto-temporal dementia and Parkinsonism linked to
chromosome 17 (FTDP-17), frontotemporal lobar degeneration, frontal
lobe dementia, hepatic encephalopathy, hereditary spastic
paraplegia, hydrocephalus, pseudotumor cerebri and other conditions
involving CSF dysfunction, Gaucher's disease, Hallervorden-Spatz
disease, Korsakoff's syndrome, mild cognitive impairment, monomelic
amyotrophy, motor neuron diseases, multiple system atrophy,
multiple sclerosis and other demyelinating conditions (eg
leukodystrophies), myalgic encephalomyelitis, myoclonus,
neurodegeneration induced by chemicals, drugs and toxins,
neurological manifestations of AIDS including AIDS dementia,
neurological/cognitive manifestations and consequences of bacterial
and/or virus infections, including but not restricted to
enteroviruses, Niemann-Pick disease, non-Guamanian motor neuron
disease with neurofibrillary tangles, non-ketotic hyperglycinemia,
olivo-ponto cerebellar atrophy, oculopharyngeal muscular dystrophy,
neurological manifestations of Polio myelitis including
non-paralytic polio and post-polio-syndrome, primary lateral
sclerosis, prion diseases including Creutzfeldt-Jakob disease
(including variant form), kuru, fatal familial insomnia,
Gerstmann-Straussler-Scheinker disease and other transmissible
spongiform encephalopathies, prion protein cerebral amyloid
angiopathy, postencephalitic Parkinsonism, progressive muscular
atrophy, progressive bulbar palsy, progressive subcortical gliosis,
progressive supranuclear palsy, restless leg syndrome, Rett
syndrome, Sandhoff disease, spasticity, sporadic fronto-temporal
dementias, striatonigral degeneration, subacute sclerosing
panencephalitis, sulphite oxidase deficiency, Sydenham's chorea,
tangle only dementia, Tay-Sach's disease, Tourette's syndrome,
vascular dementia, and Wilson disease.
[0009] Further, HDAC inhibitors as disclosed herein can potentially
provide therapeutic benefit for additional neurological disorders
in which histone deacetylase and/or transcriptional repression is
implicated or involved in the pathology. Examples include
schizophrenia, depressive disorders, bipolar disorder, and
epilepsy.
[0010] Based on their structural biological activity properties,
hydroxamic acid compounds, and methods of treating diseases either
associated with or mediated by HDAC function are disclosed.
Moreover, the compounds of the present invention avoid the
potential limitations of compounds with TSA and SAHA-like
structures in providing an effective therapy for such symptoms.
[0011] In another aspect, the present invention provides
small-molecule compounds that can function as HDAC inhibitors. The
compounds of the invention may be preferably used to inhibit
deacetylation of the N-acetyl lysine residues of histone proteins
and other transcriptional regulators. The HDAC inhibitor compounds
of the present invention are
N-substituted-1,2,3,4-tetrahydroisoquinoline hydroxamic acid
compounds.
[0012] The hydroxamic acid HDAC inhibitor compounds of the present
invention are represented by structural Formula (I). ##STR1##
[0013] wherein: [0014] X is selected from the group consisting of a
carbonyl group (C.dbd.O), or a sulfonyl group (SO.sub.2); [0015] Y
is selected from the group consisting of C.sub.1-C.sub.6 alkyl,
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR2## ##STR3## wherein:
[0016] R.sub.1 and R.sub.2 are each independently selected from the
group consisting of hydrogen, straight chain lower alkyl, and
branched lower alkyl; [0017] R.sub.1 and R.sub.2, taken together
with the nitrogen to which they are attached, form a heterocyclic
ring, wherein said heterocyclic ring is optionally substituted with
a substituted or unsubstituted lower alkyl group, or a substituted
or unsubstituted benzyl group; [0018] R.sub.3 and R.sub.4 are each
independently selected from the group consisting of hydrogen,
halogen, straight chain C.sub.1-C.sub.8 alkyl,
(R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrazolyl, wherein
R.sub.1 and R.sub.2 are as defined above; [0019] R.sub.5 is
hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; [0020] R.sub.6 is
hydrogen, lower alkyl, or benzyl; [0021] R.sub.7 is C.sub.1-C.sub.8
alkyl, benzylalkyl, heteroalkyl or heteroaralkyl; [0022] R.sub.8 is
hydrogen, --(CH.sub.2).sub.nN(R.sub.1)(R.sub.2), or OR.sub.5,
wherein R.sub.1, R.sub.2 and R.sub.5 are as defined above; [0023]
R.sub.9 is hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; [0024] Z is
--C(R.sub.3)-- or nitrogen (N), wherein R3 is as defined above; and
[0025] n is 0 to 6; or hydrates, polymorphs, or pharmaceutically
acceptable salts thereof.
[0026] The hydroxamic acid compounds of the invention can be used
as active ingredients in medicament a drug formulations for
treatment or prevention of a disease associated with HDACs. The
present invention also contemplates use of such compounds in
pharmaceutical compositions for oral or parenteral administration,
comprising one or more of the hydroxamic acid compounds disclosed
herein.
[0027] In yet another aspect, the present invention relates to a
method of treatment, including prophylactic and therapeutic
treatments, of a disease or symptoms arising from or associated
with HDACs. The invention further relates to methods of
antagonizing HDAC proteins, by administering oral or parenteral
formulations comprising the compounds of this invention by standard
methods known in the medical practice.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention concerns small molecule HDAC inhibitor
compounds. Particularly, the present invention relates to
N-substituted-1,2,3,4-tetrahydroisoquinoline hydroxamic acid
compounds capable of inhibiting HDACs, that may be used to inhibit
deacetylation of the N-acetyl lysine residues in histone proteins
and other transcriptional regulators.
[0029] As used herein, an "HDAC inhibitor" is a compound capable of
inhibiting (i.e., reduce or prevent, in whole or in part)
deacetylation of the N-acetyl lysine residues of histone proteins
and other transcriptional regulators. More specifically, an HDAC
inhibitor is a compound that is capable of inhibiting the activity
of a protein that is a member of the histone deacetylase (HDAC)
family. A compound is an "HDAC inhibitor" if it reduces HDAC
activity assayed as described herein in Example 10 by at least 10%
relative to the assay performed in the absence of that
compound.
[0030] The hydroxamic acid compounds of the present invention are
represented by Structural Formula (I). ##STR4## [0031] wherein:
[0032] X is selected from the group consisting of a carbonyl group
(C.dbd.O), or a sulfonyl group (SO.sub.2); [0033] Y is selected
from the group consisting of C.sub.1-C.sub.6 alkyl,
R.sub.1(R.sub.2)N--(CH.sub.2).sub.n--, ##STR5## wherein: [0034]
R.sub.1 and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; [0035] R.sub.1 and R.sub.2, taken together with the
nitrogen to which they are attached, form a heterocyclic ring,
wherein said heterocyclic ring is optionally substituted with a
substituted or unsubstituted lower alkyl group, or a substituted or
unsubstituted benzyl group; [0036] R.sub.3 and R.sub.4 are each
independently selected from the group consisting of hydrogen,
halogen, straight chain C.sub.1--C.sub.8 alkyl,
(R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrazolyl, wherein
R.sub.1 and R.sub.2 are as defined above; [0037] R.sub.5 is
hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; [0038] R.sub.6 is
hydrogen, lower alkyl, or benzyl; [0039] R.sub.7 is C.sub.1-C.sub.8
alkyl, benzylalkyl, heteroalkyl or heteroaralkyl; [0040] R.sub.8 is
hydrogen, --(CH.sub.2).sub.nN(R.sub.1)(R.sub.2), or OR.sub.5,
wherein R.sub.1, R.sub.2 and R.sub.5 are as defined above; [0041]
R.sub.9 is hydrogen, C.sub.1-C.sub.8 alkyl, or benzyl; [0042] Z is
--C(R.sub.3)-- or nitrogen (N), wherein R3 is as defined above; and
[0043] n is 0 to 6; or hydrates, polymorphs, or pharmaceutically
acceptable salts thereof.
[0044] In one embodiment, the hydroxamic acid compounds of the
present invention are represented by Structural Formula (I).
##STR6## wherein: [0045] X is a carbonyl group (C.dbd.O); [0046] Y
is selected from the group consisting of R.sub.1
(R.sub.2)N--(CH.sub.2).sub.n--, ##STR7## wherein: [0047] R.sub.1
and R.sub.2 are each independently selected from the group
consisting of hydrogen, straight chain lower alkyl, and branched
lower alkyl; [0048] R.sub.1 and R.sub.2, taken together with the
nitrogen to which they are attached, form a heterocyclic ring,
wherein said heterocyclic ring is optionally substituted with a
substituted or unsubstituted lower alkyl group, or a substituted or
unsubstituted benzyl group; [0049] R.sub.3 and R.sub.4 are each
independently selected from the group consisting of hydrogen,
halogen, straight chain C.sub.1-C.sub.8 alkyl,
(R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, imidazolyl, and pyrrazolyl, wherein
R.sub.1 and R.sub.2 are as defined above; [0050] R.sub.5 is
hydrogen, C.sub.1--C.sub.8 alkyl, or benzyl; [0051] R.sub.6 is
hydrogen, lower alkyl, or benzyl; [0052] R.sub.7 is C.sub.1-C.sub.8
alkyl, benzylalkyl, heteroalkyl or heteroaralkyl; [0053] Z is
--C(R.sub.3)-- or nitrogen (N), wherein R3 is as defined above; and
[0054] n is 0 to 6; or hydrates, polymorphs, or pharmaceutically
acceptable salts thereof.
[0055] The term "aryl group", as used herein, includes both
carbocyclic and heterocyclic aromatic ring systems. An aryl group
is optionally fused to a carbocyclic non-aromatic ring, a
heterocyclic non-aromatic ring, a heterocyclic aromatic ring or
another carbocyclic aromatic ring. A carbocyclic aromatic system
consists only of carbon ring atoms, preferably up to ten.
[0056] A "halogen" as used herein, includes fluorine, chlorine,
bromine and iodine atoms.
[0057] A "lower-alkyl group" as used herein, is a saturated
straight chained or branched hydrocarbon. Typically, lower-alkyl
groups have from one to eight carbons. Preferably, lower-alkyl
groups have from one to six carbon atoms.
[0058] A "cycloalkyl group" as used herein, is a non-aromatic
carbocyclic ring system that has 3 to 10 atoms. A cycloalkyl group
can optionally be fused to a carbocyclic non-aromatic ring,
carbocyclic aromatic ring, a heterocyclic aromatic ring,
non-aromatic heterocyclic ring, or another non-aromatic carbocyclic
ring. Examples of a cycloalkyl group include cyclopentyl and
cyclohexyl. Examples of a cycloalkyl ring fused with an aromatic
ring, include 1,2,3,4-tetrahydronaphthyl and
1,2,3-tetrahydroindanyl.
[0059] A "heteroalkyl group" as used herein, is a lower alkyl group
in which at least one methylene group has been replaced with a
heteroatom, such as nitrogen, oxygen, or sulfur.
[0060] A "heterocyclic group" or "heterocyclic ring" as used
herein, is a ring system that has 3 to 10 atoms and includes at
least one heteroatom, such as nitrogen, oxygen, or sulfur. A
heterocyclic group can include a "heterocycloalkyl group" and a
"heteroaryl group".
[0061] A "heterocycloalkyl group" or a "non-aromatic heterocyclic
group", as used herein, is a non-aromatic ring system that has 3 to
10 atoms and includes at least one heteroatom, such as nitrogen,
oxygen, or sulfur. A heterocycloalkyl group is optionally fused to
a carbocyclic non-aromatic ring, carbocyclic aromatic ring, a
heterocyclic aromatic ring, or another non-aromatic heterocyclic
ring. Examples of heterocycloalkyl groups include piperazinyl,
piperidinyl, homopiperazinyl, quinuclidinyl, azetidinyl,
morpholinyl, thiomorpholinyl, thiazolidinyl,
1,2,3,4-tetrahydroquinolinyl, 1,2,3-tetrahydroindolyl, indolyl,
furanyl or imidazolyl.
[0062] A "heteroaryl group" or an "aromatic heterocyclic group", as
used herein, is an aryl group that has 3 to 10 ring atoms including
one or more ring heteroatoms such as nitrogen, oxygen and sulfur. A
heteroaryl group can be monocyclic. Alternatively, a monocyclic
heteroaryl group is fused to one or more other monocyclic
heteroaryl groups or monocyclic carbocyclic aryl groups. Preferably
a heteroaryl group has 1 to 3 heteroatoms. A heteroaryl group is
optionally fused to a carbocyclic aromatic ring, carbocyclic
non-aromatic ring or another heteroaryl ring. Examples of a
heteroaryl group include but are not limited to thienyl, pyridyl,
pyrazolyl, isoxazolyl, thiadiazolyl, oxadiazolyl, indazolyl, furyl,
pyrrolyl, imidazolyl, pyrazolyl, triazolyl, pyrimidinyl,
pyridazinyl, pyrazinyl, thiazolyl, isoxazolyl, isothiazolyl,
tetrazolyl, oxazolyl, oxadiazolyl, quinolinyl, carbazolyl,
benzocarbazolyl, benzotriazolyl, benzimidazole, benzothiophene,
benzofuran or indolyl.
[0063] An "aralkyl" group refers to an aryl-alkyl group having from
about 7 to about 15 carbon atoms. Examples of aralkyl groups
include, but are not limited to, benzyl, phenethyl, benzydryl, and
naphthylmethyl.
[0064] A "heteroaralkyl" group refers to an aryl-alkyl group having
from about 4 to about 15 carbon atoms, including one or more ring
heteroatoms such as nitrogen, oxygen and sulfur.
[0065] Suitable substituents on a substituted benyzlalkyl group,
substituted lower-alkyl group, substituted heteroalkyl group,
substituted cycloalkyl group, substituted heterocycloalkyl group,
substituted aryl group, substituted heteroaryl group, substituted
aralkyl group, substituted heteroaralkyl group include for example
but are not limited to, hydrogen, halogen, an electron withdrawing
group, a hydroxy group, an alkoxy group, a lower alkyl group, a
cycloalkyl group, a heterocycloalkyl group, an aryl group, a
heteroaryl group, an aralkyl group, a heteroaralkyl group,
(R.sub.1)(R.sub.2)N--(CH.sub.2).sub.n--,
NH.sub.2--C(.dbd.NH)--NH--, OR.sub.5, CF.sub.3, NO.sub.2,
R.sub.7--C(.dbd.O)N(R.sub.6)--, and imidazolyl. R.sub.1, R.sub.2,
R.sub.5 R.sub.6 and R.sub.7 are as defined above;
[0066] A substituted lower-alkyl group, substituted heteroalkyl
group, substituted cycloalkyl group, substituted heterocycloalkyl
group, substituted aryl group, substituted heteroaryl group,
substituted aralkyl group, substituted heteroaralkyl group can have
more than one substituent.
[0067] Currently preferred hydroxamic acid HDAC inhibitor compounds
include, but are not limited to: [0068]
2-(4-guanidino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide, [0069]
2-(4-dimethylamino-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide, [0070]
2-(quinoline-8-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide, [0071]
2-((4-dimethylamino-phenyl)-acetyl)-1,2,3,4-tetrahydro-isoquinoline-7-car-
boxylic acid hydroxyamide, [0072]
2-(4-dimethylamino-butyryl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide, or [0073]
2-(4-imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-isoquinoline-7-carboxylic
acid hydroxyamide.
[0074] The hydroxamic acid HDAC inhibitor compounds of the present
invention can exist as water soluble salts, polymorphic crystalline
forms, and in some cases as optically active stereoisomers and
their racemates. All such variants including physiologically
acceptable salts and isomers of such compounds are within the scope
of the claims.
[0075] Salts of compounds containing an amine or other basic group
can be obtained, for example, by reacting with a suitable organic
or mineral acid, such as for example hydrochloric acid, perchloric
acid, acetic acid, citric acid, maleic acid, and the like.
Compounds with a quaternary ammonium group also contain a
counter-ion such as chloride, bromide, iodide, acetate, perchlorate
and the like. Salts of compounds containing a carboxylic acid or
other acidic functional group can be prepared by reaction with a
suitable base, for example, a alkali metal hydroxide base. Salts of
acidic functional groups contain a counter-ion such as sodium,
potassium, ammonium, calcium and the like.
[0076] The hydroxamic acid HDAC inhibitor compounds of the present
invention can be synthesized by using a combination of any suitable
method known in the art. In one embodiment, a typical synthetic
process for obtaining compounds of the invention is carried out as
shown in Scheme 1. ##STR8##
[0077] 7-Amino-1,2,3,4-tetrahydroisoquinoline 3 and
6-Cyanotetrahydroquinoline 4 is obtained by subjecting readily
available 1,2,3,4-tetrahydroisoquinoline 1 to a series of steps
known in the art in the art (See for example, Grunewald et al., J.
Med. Chem. 1997, 40, 3997-4005, the contents of which is
incorporated herein by reference in its entirety).
6-Cyanotetrahydroquinoline 4 is then reacted with an aliphatic
alcohol, such as for example, methanol (MeOH) and hydrochloric acid
(HCl) to form 7-Methoxycarbonyltetrahydroiosquinoline 5.
Methoxycarbonyltetrahydroiosquinoline 5 is then reacted with a
carboxylic acid YCO.sub.2H (V) to form amide 6. Y is as described
above. Examples of preferred carboxylic acids (V) include but are
not limited to compounds 10-47 listed in Table 1. Amide 6 is
subsequently reacted in the presence of an alcoholic base solution,
(such as for example, sodium hydroxide (NaOH) in methanol (MeOH)).
with 1-benzotriazolyoxytris(dimethylamino)phosphonium
hexafluorophosphate (Castro's Reagent) (BOP), triethylamine
(Et.sub.3N) in N,N-dimethylformamide (DMF) to form hydroxamic acid
8, a Formula I compound.
[0078] Alternatively, methoxycarbonyltetrahydroiosquinoline 5 is
reacted with a sulfonyl chloride YSO.sub.2Cl (VIII) to form the
corresponding sulfonyl compound 7 as shown in Scheme 2. Examples of
preferred sulfonyl chloride compounds include but are not limited
to compounds 48-67 as listed in Table 2. Sulfonyl 7 is subjected to
the same sequence of reactions as amide 6 to give hydroxamic acid
9, a Formula I compound. ##STR9##
[0079] The synthetic process described above is intended to
exemplify a method of obtaining a hydroxamic acid HDAC inhibitor
compound of the invention to one skilled in the art, and is not
intended to, in any way, limit the scope of the invention.
TABLE-US-00001 TABLE 1 Carboxylic Acids of Formula YCO.sub.2H (V)
Compound Number. Chemical Name 10 4-(dimethylamino)benzoic acid 11
3-(dimethylamino)benzoic acid 12 8-quinolinecarboxylic acid 13
4-biphenylcarboxylic acid 14 4-(dimethylamino)phenylacetic acid 15
9-fluorenone-2-carboxylic acid 16
4'-(octyloxy)-4-biphenylcarboxylic acid 17
4-(dimethylamino)cinnamic acid 18 9-fluoreneacetic acid 19
1-naphthylacetic acid 20 2-naphthylacetic acid 21 1-naphthoic acid
22 2-naphthoic acid 23 4-(dimethylamino)butyric acid hydrochloride
24 3-quinolinecarboxylic acid 25 4-(1H-imidazol-1-yl)benzoic acid
26 4-(1H-pyrrol-1-yl)benzoic acid 27
2-hydroxy-5-(1H-pyrrol-1-yl)benzoic acid 28
4-(N-(2,4-diamino-6-pteridinylmethyl)-N- methylamino)benzoic acid
29 4-imidazolecarboxylic acid 30 4-(dimethylamino)butyric acid 31
6-methoxy-1,2,3,4-tetrahydro-9H-pyrido[3,4b]-indo carboxylic acid
32 trans-3-indoleacrylic acid 33 4-acetamidobenzoic acid 34
4-guanidinobenzoic acid hydrochloride 35 indole-5-carboxylic acid
36 cyclohexane carboxylic acid 37 cis-4-amino-1-cyclohexane
carboxylic acid 38 trans-4-(aminomethyl)cyclohexane carboxylic acid
39 4-methoxycyclohexane carboxylic acid 40 2-amino-3-norbornane
carboxylic acid 41 1-amino-1-cyclohexane carboxylic acid 42
2-amino-1-cyclohexane carboxylic acid 43
4'-hydroxy-4-biphenylcarboxylic acid 44
(S)-(-)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3- carboxylic
acid 45 5-methoxy-2-methyl-3-indole acetic acid 46 3-indolebutyric
acid 47 1-methyl-3-indole acetic acid
[0080] TABLE-US-00002 TABLE 2 Sulfonyl Chlorides of Formula
YSO.sub.2C1 (VIII) Compound Number Chemical Name 48 benzene
sulfonyl chloride 49 biphenyl-4-sulfonyl chloride 50 1-naphthalene
sulfonyl chloride 51 N-acetyl sulfanilyl chloride 52
4-chlorobenzene sulfonyl chloride 53 2-naphthalene sulfonyl
chloride 54 trans-beta-styrenesulfonyl chloride 55
alpha-toluenesulfonyl chloride 56 4-nitorbenzenesulfonyl chloride
57 3,4-dimethoxybenzenesulfonyl chloride 58
4-methoxybenzenesulfonyl chloride 59 8-quinoline sulfonyl chloride
60 2-thiophene sulfonyl chloride 61 3,5-dichlorobenzenesulfonyl
chloride 62 3,4-difluorobenzenesulfonyl chloride 63
4-(trifluoromethyl)benzenesulfonyl chloride 64 dansyl chloride 65
4-bromobenzenesulfonyl chloride 66
4-(dimethylamino)azobenzene-4'-sulfonyl chloride 78
2-acetamideo-4-methyl-5-thiazolesulfonyl chloride
[0081] TABLE-US-00003 TABLE 3 Hydroxamic Acid HDAC Inhibitor
Compounds* Compound Number Product 68
2-(4-Acetylamino-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 69
2-(4-Guanidino-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 70
2-(1H-Indole-5-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 71
2-(4-Cyclohexanecarbonyl-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 72
2-(4-Amino-cyclohexanecarbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 73
2-(4-Aminomethyl-cyclohexanecarbonyl)-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide 74
2-(4-Methoxy-cyclohexanecarbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 75
2-(3-Amino-bicyclo[2.2.1]heptane-2-carbonyl)-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide 76
2-(1-Amino-cyclohexanecarbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 77
2-(2-Amino-cyclohexanecarbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 78
2-(4'-Hydroxy-biphenyl-4-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 79
2-(2,3,4,9-Tetrahydro-1H-.beta.-carboline-3-carbonyl)-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide 80
2-[(5-Methoxy-3-methyl-1H-indol-2-yl)-acetyl]-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide 81
2-(4-1H-Indol-2-yl-butyryl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 82
2-[(1H-Indol-2-yl)-acetyl]-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 83
2-(4-Dimethylamino-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 84
2-(3-Dimethylamino-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 85
2-(Quinoline-8-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 86
2-(Biphenyl-4-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 87
2-[(4-Dimethylamino-phenyl)-acetyl]-1,2,3,4-tetrahydro
isoquinoline-7-carboxylic acid hydroxyamide 88
2-(9-Oxo-9H-fluorene-2-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 89
2-(4'-Octyloxy-biphenyl-4-carbonyl)-1,2,3,4-tetrahydro- 1
isoquinoline-7-carboxylic acid hydroxyamide 90
2-[3-(4-Dimethylamino-phenyl)-acryloyl]-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide 91
2-[(9H-Fluoren-9-yl)-acetyl]-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 92
2-(Naphthalen-1-yl-acetyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 93
2-(Naphthalen-2-yl-acetyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 94
2-(Naphthalene-1-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 95
2-(Naphthalene-2-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 96
2-(4-Dimethylamino-butyryl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 97
2-(Quinoline-3-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 98
2-(4-Imidazol-1-yl-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 99
2-(4-Pyrrol-1-yl-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 100
2-(2-Hydroxy-4-pyrrol-1-yl-benzoyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 101
2-{4-[(5,7-Diamino-pyrido[3,4-b]pyrazin-3-ylmethyl)-
methyl-amino]-benzoyl}-1,2,3,4-tetrahydro-isoquinoline-7-
carboxylic acid hydroxyamide 102
2-(1H-Imidazole-4-carbonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 103
2-(4-Dimethylamino-butyryl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 104
2-(6-Methoxy-2,3,4,4a,9,9a-hexahydro-1H-.beta.-carboline-
1-carbonyl)-1,2,3,4-tetrahydro-isoquinoline-7- carboxylic acid
hydroxyamide 105 2-(3-1H-Indol-3-yl-acryloyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 106
2-Benzenesulfonyl-1,2,3,4-tetrahydro- isoquinoline-7-carboxylic
acid hydroxyamide 107 2-(Biphenyl-4-sulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 108
2-(Naphthalene-1-sulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 109
2-(4-Acetylamino-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 110
2-(4-Chloro-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 111
2-(Naphthalene-2-sulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 112
2-(2-Phenyl-ethenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 113
2-Phenylmethanesulfonyl-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 114
2-(4-Nitro-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 115
2-(3,4-Dimethoxy-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 116
2-(4-Methoxy-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 117
2-(Quinoline-8-sulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 118
2-(Thiophene-2-sulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 119
2-(3,5-Dichloro-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 120
2-(3,4-Difluoro-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 121
2-(4-Trifluoromethyl-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 122
2-(5-Dimethylamino-naphthalene-1-sulfonyl)-1,2,3,4-
tetrahydro-isoquinoline-7-carboxylic acid hydroxy amide 123
2-(4-Bromo-benzenesulfonyl)-1,2,3,4-tetrahydro-
isoquinoline-7-carboxylic acid hydroxyamide 124
2-[4-(4-Dimethylamino-phenylazo)-benzenesulfonyl]-
1,2,3,4-tetrahydro-isoquinoline-7- carboxylic acid hydroxyamide 125
2-(2-Acetylamino-4-methyl-thiazole-5-sulfonyl)-
1,2,3,4-tetrahydro-isoquinoline-7-carboxylic acid hydroxyamide
*Compounds 68-105 (Example 7); compounds 106-125 (Example 8)
[0082] In another embodiment, the Formula I compounds may be
prepared as a hydroxamic acid HDAC inhibitor library that can be
utilized in screening methods known in the art. A process for the
synthesis of library members is shown in Scheme 3, by way of
example. ##STR10##
[0083] 6-Cyanotetrahydroquinoline 4 is converted to
6-carboxytetrahydroquinoline II following any suitable method
described in the art. See for example, Grunewald et al., J. Med.
Chem. 1999, 42, 118-134, the contents of which is incorporated
herein by reference in its entirety. 6-Carboxytetrahydroquinoline
II is reacted with a polymeric resin (P) to give resin-immobilized
tetrahydroquinoline III. Alternatively,
6-Carboxytetrahydroquinoline II is converted to the corresponding
acid chloride followed by reaction with the polymeric resin (P) to
give resin-immobilized tetrahydroquinoline III. Resin-immobilized
tetrahydroquinoline III is reacted with an acyl halide IV.
Alternatively, resin-immobilized tetrahydroquinoline III is reacted
with a carboxylic acid V in the presence of a coupling reagent such
as benzotriazol-1-yl-oxytripyrrolidinophosphonium
hexafluorophosphate (PyBop), N,N'-carbonyldiimidazole,
1-cyclohexyl-3-3 (2-morpholinomethyl)-carbodiimide,
N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide (EDC), and
dicyclohexylcarbodiimide (DCC), to form N-acetyltetrahydroquinoline
VI. N-acetyltetrahydroquinoline VI is reacted with
(CH.sub.3).sub.2(OCH.sub.3)ONH.sub.2, to form a
(1-methoxy-1-methyl-ethoxy)-amide VII.
(1-methoxy-1-methyl-ethoxy)-amide VII is reacted with a
deprotecting compound such as pyridinium para-toluenesulfonate
(PPTS) (See for example, Sternson et al., Org. Lett., 2001, 26,
4239-4242, the contents of which is incorporated herein by
reference in its entirety) to form hydroxamic acid compound 9, a
Formula I compound.
[0084] The HDAC inhibition activity of the hydroxamic acid
compounds of the present invention is assessed by standard assaying
methods used in the art, such as for example, the one described by
Carmen, et. al. J. Biol. Chem. 1996, 271, 15837-15844, the contents
of which is incorporated herein by reference in its entirety. The
inhibition of HDAC is assayed using [.sup.3H]-labeled acetylated
histones prepared in Jurkat_T cells which is used as the enzyme
substrate. The hydroxamic acid HDAC inhibitor compounds of the
present invention, dissolved in an appropriate solvent such as
dimethylsulfoxide (DMSO), are pre-incubated with recombinant HDACl
enzyme for about 30 minutes at about 4.degree. C. in buffer
containing about 40 mM Tris-Cl, pH of about 7.6, about 20 mM EDTA
and about 50% glycerol. At about 37.degree. C., the
[.sup.3H]-labeled acetylated histones are added and incubated for
about 10 minutes. The released [.sup.3H]-acetic acid is then
extracted and quantified by scintillation count.
[0085] The assay described above is intended to exemplify one of
several methods available for assessing the biological activity of
hydroxamic acid HDAC inhibitor compounds of the invention to one
skilled in the art, and is not intended, in any way, to limit the
scope of the applicability of such assays to the compounds of the
invention.
[0086] The hydroxamic acid HDAC inhibitor compound of the invention
may be administered by any of the suitable routes to a mammal that
are medically acceptable. The HDAC inhibitor compound is preferably
administrated orally (e.g., dietary) in capsules, suspensions or
tablets. Methods for encapsulating compositions (such as in a
coating of hard gelatin or cyclodextran) are known in the art
(Baker, et al., "Controlled Release of Biological Active Agents",
John Wiley and Sons, 1986). The hydroxamic acid HDAC inhibitor
compounds can be administered to the subject in conjunction with an
acceptable pharmaceutical carrier as part of a pharmaceutical
composition. The formulation of the pharmaceutical composition will
vary according to the route of administration selected. Suitable
pharmaceutical carriers may contain inert ingredients which do not
interact with the compound. The carriers should be biocompatible,
i.e., non-toxic, non-inflammatory, non-immunogenic and devoid of
other undesired reactions at the administration site. Examples of
pharmaceutically acceptable carriers include, for example, saline,
commercially available inert gels, or liquids supplemented with
albumin, methyl cellulose or a collagen matrix. Standard
pharmaceutical formulation techniques can be employed, such as
those described in "Remington: The Science and practice of
Pharmacy", 20.sup.th ed. (2000), Lippincott, Williams &
Wilkins, Philadelphia, Pa.
[0087] A "mammal" as described herein refers to both human and
animal species in need of administration of an HDAC inhibitor.
[0088] As referred to herein, mammals "in need of administration"
with HDAC inhibiting compounds, are those affected with symptoms or
conditions that are treatable with HDAC inhibitors in a mammal as
shown to be beneficial therapeutically or prophylactically. A
beneficial outcome resulting from such treatment, may include, but
is not limited to either a decrease in the severity of symptoms or
delay in the onset of symptoms, or a substantial reversal of the
symptom or condition.
[0089] The suitability of a given HDAC inhibitor compound for
treatment of neurodegenerative disease can be assessed in any of a
number of animal models for neurodegenerative disease. For example,
mice transgenic for an expanded polyglutamine repeat mutant of
ataxin-1 develop ataxia typical of spinocerebellar ataxia type 1
(SCA-1) are known (Burright et al., 1995, Cell 82: 937-948;
Lorenzetti et al., 2000, Hum. Mol. Genet. 9: 779-785; Watase, 2002,
Neuron 34: 905-919), and can be used to determine the efficacy of a
given compound in the treatment or prevention of neurodegenerative
disease. Additional animal models, for example, for Huntington's
disease (see, e.g., Mangiarini et al., 1996, Cell 87: 493-506, Lin
et al., 2001, Hum. Mol. Genet. 10: 137-144), Alzheimer's disease
(Hsiao, 1998, Exp. Gerontol. 33: 883-889; Hsiao et al., 1996,
Science 274: 99-102), Parkinson's disease (Kim et al., 2002, Nature
418: 50-56), amyotrophic lateral sclerosis (Zhu et al., 2002,
Nature 417: 74-78), Pick's disease (Lee & Trojanowski, 2001,
Neurology 56 (Suppl. 4): S26-S30, and spongiform encephalopathies
(He et al., 2003, Science 299: 710-712) are known and can also be
used to evaluate the efficacy of HDAC inhibitors in a similar
manner.
[0090] Animal models are not limited to mammalian models. For
example, Drosophila strains provide accepted models for a number of
neurodegenerative disorders (reviewed in Fortini & Bonini,
2000, Trends Genet. 16: 161-167; Zoghbi & Botas, 2002, Trends
Genet. 18: 463-471). These models include not only mutants bearing
mutated fly genes, but also mutants bearing human transgenes with
targeted mutations. Among the Drosophila models available are, for
example, Spinocerebellar ataxias (e.g., SCA-1 (see, e.g., WO
02/058626), SCA-3 (Warrick et al., 1998, Cell 93: 939-949)),
Huntington's disease (Kazemi-Esfarjani & Benzer, 2000, Science
287: 1837-1840), Parkinson's disease (Feany et al., 2000, Nature
404: 394-398; Auluck et al., 2002, Science 295: 809-810),
age-dependent neurodegeneration (Palladino et al., 2002, Genetics
161: 1197-1208), Alzheimer's disease (Selkoe et al., 1998, Trends
Cell Biol. 8: 447-453; Ye et al., 1999, J. Cell Biol. 146:
1351-1364), amyotrophic lateral sclerosis (Parkes et al., 1998,
Nature Genet. 19: 171-174) and adrenoleukodystrophy.
[0091] Animals administered the compounds are evaluated for
symptoms relative to animals not administered the compounds. A
change in the severity of symptoms (e.g., a 10% or greater
improvement in one or more symptoms), or a delay in the onset of
symptoms, in treated versus untreated animals is indicative of
therapeutic efficacy.
[0092] Dosage and Administration
[0093] An "effective amount" as referred to herein, relates to the
amount of HDAC inhibitor compound (dose) that is capable of
rendering a beneficial clinical outcome of the condition being
treated with the HDAC inhibitor compound of the invention compared
with the absence of such treatment. The effective amount of HDAC
inhibitor compound administered will depend on the degree,
severity, and type of the disease or condition, the amount of
therapy desired, and the release characteristics of the
pharmaceutical formulation. It will also depend on the subject's
health, size, weight, age, sex and tolerance to specific compounds,
which are determinable pharmaceutical parameters to those skilled
in the field. Generally, treatment is considered "effective" if one
or more symptoms of the disease or disorder improves (e.g., at
least 10% relative to pre-treatment) during the course of
treatment. The compounds of the invention can also be given to
prevent or delay the onset of symptoms in an individual predisposed
to such disorder, e.g., one predisposed to Huntington's chorea. A
delay or absence of the onset of symptoms relative to the time one
would expect such symptoms to arise in a similar individual not
treated with the drug would indicate efficacy.
[0094] The present invention provides for pharmaceutical
compositions comprising a therapeutically effective amount of an
HDAC inhibitor as disclosed herein, in combination with a
pharmaceutically acceptable carrier or excipient. The HDAC
inhibitors employed in the present invention can be administered by
oral or parenteral routes, including intravenous, intramuscular,
intraperitoneal, subcutaneous, transdermal, airway (aerosol),
rectal, vaginal and topical (including buccal and sublingual)
administration.
[0095] For oral administration, the compounds useful in the
invention will generally be provided in the form of tablets or
capsules, as a powder or granules, or as an aqueous solution or
suspension.
[0096] Tablets for oral use may include the active ingredients
mixed with pharmaceutically acceptable excipients such as inert
diluents, disintegrating agents, binding agents, lubricating
agents, sweetening agents, flavoring agents, coloring agents and
preservatives. Suitable inert diluents include sodium and calcium
carbonate, sodium and calcium phosphate, and lactose, while corn
starch and alginic acid are suitable disintegrating agents. Binding
agents may include starch and gelatin, while the lubricating agent,
if present, will generally be magnesium stearate, stearic acid or
talc. If desired, the tablets may be coated with a material such as
glyceryl monostearate or glyceryl distearate, to delay absorption
in the gastrointestinal tract.
[0097] Capsules for oral use include hard gelatin capsules in which
the active ingredient is mixed with a solid diluent, and soft
gelatin capsules wherein the active ingredients is mixed with water
or an oil such as peanut oil, liquid paraffin or olive oil.
[0098] Formulations for rectal administration may be presented as a
suppository with a suitable base comprising for example cocoa
butter or a salicylate.
[0099] Formulations suitable for vaginal administration may be
presented as pessaries, tampons, creams, gels, pastes, foams or
spray formulations containing in addition to the active ingredient
such carriers as are known in the art to be appropriate.
[0100] For intramuscular, intraperitoneal, subcutaneous and
intravenous use, the compounds of the invention will generally be
provided in sterile aqueous solutions or suspensions, buffered to
an appropriate pH and isotonicity. Suitable aqueous vehicles
include Ringer's solution and isotonic sodium chloride. Aqueous
suspensions according to the invention may include suspending
agents such as cellulose derivatives, sodium alginate,
polyvinyl-pyrrolidone and gum tragacanth, and a wetting agent such
as lecithin. Suitable preservatives for aqueous suspensions include
ethyl and n-propyl p-hydroxybenzoate.
[0101] The compounds useful according to the invention may also be
presented as liposome formulations.
[0102] In general a suitable dose will be in the range of 0.01 to
100 mg per kilogram body weight of the recipient per day,
preferably in the range of 0.2 to 10 mg per kilogram body weight
per day. The desired dose is preferably presented once daily, but
may be dosed as two, three, four, five, six or more sub-doses
administered at appropriate intervals throughout the day. These
sub-doses may be administered in unit dosage forms, for example,
containing 10 to 1500 mg, preferably 20 to 1000 mg, and most
preferably 50 to 700 mg of active ingredient per unit dosage
form.
[0103] In addition to their administration singly, the compounds
useful according to the invention can be administered in
combination with other known inhibitors of HDAC activity. In any
event, the administering physician can adjust the amount and timing
of drug administration on the basis of observations of one or more
symptoms (e.g., motor or cognitive function as measured by standard
clinical scales or assessments) of the disorder being treated.
[0104] The invention is illustrated by the following examples which
are not intended to be limiting in any way.
EXAMPLES
Example 1
7-Nitro-1,2,3,4-tetrahydroisoquinoline hydrochloride (2)
[0105] 1,2,3,4-tetrahydroiosquinoline (Aldrich T1,300-5, 100 gm)
(11.6 g, 84.8 mmol) is added dropwise with care to stirred ice-cold
concentrated H.sub.2SO.sub.4 (42.0 mL). Potassium nitrate (9.40 g.,
93 mmol) is then added in small portions, taking care that the
temperature of the reaction mixture does not rise above 5.degree.
C. After stirring overnight at room temperature the dark brown
reaction mixture is added carefully to a stirred ice-cold
concentrated NH.sub.4OH solution. The basic red reaction mixture is
extracted with chloroform (three times), and the combined
chloroform extracts is washed with brine and dried over anhydrous
Na.sub.2SO.sub.4. Evaporation of the solvent gives a dark brown oil
(14.6 g) which was taken up in EtOH (65 mL) and cooled in an ice
bath. Treatment of this reddish solution with concentrated HCl (11
mL) yields a viscous yellow precipitate of the hydrochloride salt
which is filtered and crystallized from methanol (250 mL) to yield
the product compound (2) as a solid (5.36 g, .about.30% yield).
Alternatively, flash chromatography may be used to purify the crude
reaction mixture before crystallization.
Example 2
7-Amino-1,2,3,4-tetrahydroisoquinoline dihydrochloride (3)
[0106] 7-Nitro-1,2,3,4-tetrahydroisoquinoline hydrochloride (2)
from Example 1, is placed in a Parr shaker bottle (15.0 g, 69.9
mmol) dissolved in 95% EtOH (100 mL), and to the Parr shaker bottle
is added concentrated HCl (10 mL), water (25 mL), and PtO.sub.2
(0.5 g). The mixture is hydrogenated at 50 psi until no further
drop in pressure was observed (about 4 hours). The yellowish
suspension is filtered through Celite and evaporated to dryness to
afford a yellowish solid which is made basic with 10% NaOH solution
(adequate care is exercised in catalyst disposal). Extraction of
the basic solution with CHCl.sub.3 (three times), followed by
drying over anhydrous Na.sub.2SO.sub.4 and evaporation of the
solvent, yields a reddish yellow solid (9.54 g, 92.2%): mp=110-112.
7-Amino-1,2,3,4-tetrahydroisoquinoline dihydrochloride (3) is
recrystallized from aqueous MeOH as buff colored needles,
mp=290.degree. C.
Example 3
7-Cyano-1,2,3,4-tetrahydroisoquinoline Hydrochloride (4)
[0107] 7-Amino-1,2,3,4-tetrahydroisoquinoline dihydrochloride (3)
from Example 2 (0.75 g, 5.1 mmol) is dissolved in concentrated HCl
(1.75 mL) and water (2 mL) and stirred in an ice bath, giving a red
solution. To this solution is added dropwise NaNO.sub.2 (0.35 g,
5.1 mmol) dissolved in water (2 mL). After 15 minutes stirring, a
positive starch-iodide test is obtained and the excess HNO.sub.2 is
destroyed by the addition of urea (0.10 g).
[0108] In a second flask, a solution of NaOH (0.50 g in 1.5 mL
water) and KCN (1.63 g in 5 mL of water) is prepared, and benzene
(5 mL) is added. The suspension is chilled in an ice bath, and to
it is added a solution of Ni.sub.2SO.sub.4.6H.sub.2O (1.3 g, 5
mmol) in 2.5 mL water). The color of the resulting mixture changes
to yellow-brown. To this mixture is added dropwise with vigorous
stirring the diazotized solution. Brisk evolution of N.sub.2 is
observed, and the reaction mixture is allowed to warm to room
temperature over a period of 2 hours. The mixture is warmed to
50.degree. C. in an oil bath for 1 hour, cooled to room
temperature, made basic with 1 N NaOH, and filtered through Celite.
The Celite bed is washed with methylene chloride, the filtrate is
extracted with methylene chloride (three times), and the combined
organic layers are washed with brine. Removal of the solvent after
drying with Na.sub.2SO.sub.4 gives a dark black oil (0.60 g) which
is distilled bulb to bulb (100-105.degree. C., 0.15 mm Hg using a
Kugelrohr or similar apparatus) to afford a colorless oil (0.30 g)
which solidifies on cooling. The compound may be further purified
by flash chromatography or prep HPLC. The resulting
7-Cyano-1,2,3,4-tetrahydroisoquinoline hydrochloride (4) is a
colorless solid, m.p.=92-94.degree. C.
Example 4
7-Methoxycarbonyl-1,2,3,4-tetrahydroiosquinoline hydrochloride
(5)
[0109] 7-Cyano-1,2,3,4-tetrahydroisoquinoline Hydrochloride (4)
from Example 3 (0.205 g, 1.29 mmol) is added to a saturated
methanolic HCl solution (20 mL, prepared by bubbling HCl in dry
MeOH), and to the resulting suspension is added water (0.03 mL).
The mixture is heated to reflux for 18 hours. The solution is
cooled, and the solvent removed on a rotary evaporator to yield a
colorless solid which is treated with 5% NaHCO.sub.3. The solution
was extracted with methylene chloride, dried over anhydrous
Na.sub.2SO.sub.4, and evaporated to give a colorless semisolid
(0.243 g, 98%). Recrystallization from methylene chloride-hexane
produces white needles of
7-Methoxycarbonyl-1,2,3,4-tetrahydroiosquinoline hydrochloride (5),
m.p.=216-218.degree. C.
Example 5
7-Methoxycarbonyl-1-[arylcarbonyl or
alkylcarbonyl)-1,2,3,4-tetrahydroisoquinoline hydrochloride (6)
[0110] Experimental conditions are those of standard coupling of
acids (see Table 1) to amines. Alternatively, in several cases acid
chlorides may be used in place of carboxylic acids. Table 1 shows
carboxylic acid compounds 10-47.
Example 6
7-Methoxycarbonyl-1-[arylsulfonyl or
alkylsulfonyl)-1,2,3,4-tetrahydroisoquinoline hydrochloride (7)
[0111] Experimental conditions are those of standard conditions for
reacting sulfonyl chlorides (see Table 2) with amines to give
sulfonamides. Table 2 shows sulfonyl chloride compounds 48-67.
Example 7
7-N-hydroxyamide-1-[arylcarbonyl or
alkylcarbonyl]-1,2,3,4-tetrahydroisoquinoline (8)
[0112] To a solution of compound (6) from Example 5, (2 mmol) in
methanol (.about.10 mL) is added at room temperature a 5% sodium
hydroxide solution (10 mL). The mixture is stirred at room
temperature for 4 hours. The solvent is evaporated and the residue
diluted with water. The mixture is washed with methylene chloride,
acidified with 10% HCl, extracted with ethyl acetate, then dried
over MgSO.sub.4. The solvent is evaporated to give the carboxylic
acid.
[0113] To a solution of the carboxylic acid (1 mmol) in DMF (10 mL)
is added (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride (248 mg, 1.3 mmol) and hydroxybenzotriazole hydrate
(162 mg, 1.2 mmol). The mixture is stirred at room temperature for
2 hours. Hydroxylamine hydrochloride (348 mg, 5 mmol) is added
followed by triethylamine (696 .mu.L, 5 mmol). After the mixture is
stirred at room-temperature overnight, the solvent is evaporated.
Water is added, and the mixture is extracted with EtOAc. The
organic layer is washed with saturated solution of NaHCO.sub.3 and
brine, dried over MgSO.sub.4, and evaporated to dryness. The
residue is purified by column chromatography on silica gel with
CH.sub.2CL.sub.2/MeOH to give 7-N-hydroxyamide-1-[arylcarbonyl or
alkylcarbonyl]-1,2,3,4-tetrahydroisoquinoline (8). Products 68-105
are shown in FIG. 3.
Example 8
7-N-hydroxyamide-1-[arylsulfonyl or
alkylsulfonyl]-1,2,3,4-tetrahydroisoquinoline (9)
[0114] To a solution of compound (7) from Example 6, (2 mmol) in
methanol (.about.10 mL) is added at room temperature a 5% sodium
hydroxide solution (10 mL). The mixture is stirred at room
temperature for 4 hours. The solvent was evaporated and the residue
diluted with water. The mixture is washed with methylene chloride,
acidified with 10% HCl, extracted with ethyl acetate, then dried
over MgSO.sub.4. The solvent is evaporated to give the carboxylic
acid.
[0115] To a solution of the carboxylic acid (1 mmol) in DMF (10 mL)
is added (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride (248 mg, 1.3 mmol) and hydroxybenzotriazole hydrate
(162 mg, 1.2 mmol). The mixture is stirred at room temperature for
2 hours. Hydroxylamine hydrochloride (348 mg, 5 mmol) is added
followed by triethylamine (696 .mu.L, 5 mmol). After the mixture is
stirred at room-temperature overnight, the solvent is evaporated.
Water is added, and the mixture is extracted with EtOAc. The
organic layer is washed with saturated solution of NaHCO.sub.3 and
brine, dried over MgSO.sub.4, and evaporated to dryness. The
residue is purified by column chromatography on silica gel with
CH.sub.2Cl.sub.2/MeOH to give 7-N-hydroxyamide-1-[arylsulfonyl or
alkylsulfonyl]-1,2,3,4-tetrahydroisoquinoline (9). Products 106-125
are shown in FIG. 3.
Example 9
Synthetic Approach for Combinatorial Library Hydroxamic Acid HDAC
Inhibitors
[0116] A synthesis of a library of HDAC inhibitors based on the
7-carboxyl-isoquinoline scaffold is shown in Scheme 2 below.
6-Cyanotetrahydroquinoline 4 is obtained by methods disclosed in
the art. See for example, Grunewald et al., J. Med. Chem. 1997, 40,
3997-4005, the contents of which is incorporated herein by
reference in its entirety. 6-Cyanotetrahydroquinoline 4 is
converted to 6-Carboxytetrahydroquinoline II following the method
described in the art by Grunewald et al., J. Med. Chem. 1999, 42,
118-134, the contents of which is incorporated herein by reference
in its entirety. Attachment of 6-Carboxytetrahydroquinoline II to a
resin to give resin-imobilized tetrahydroquinoline III and
subsequent acylation in a combinatorial fashion with a variety or
acids or acid chlorides is standard chemistry with many
experimental examples known in the art. Resin-bound esters of the
type VI can be aminated and cleaved from resin with reagents such
as amines and (CH.sub.3).sub.2(OCH.sub.3)ONH.sub.2.
(1-methoxy-1-methyl-ethoxy)-amide VII is converted to the
corresponding hydroxamic acid 9, following the method described by
Sternson et al., Org. Lett., (2001) 26, 4239-4242.
Example 10
HDAC Inhibition Assay
[0117] Inhibition of HDAC is assayed using [.sup.3H]-labeled
acetylated histones prepared in Jurkat_T cells used as the enzyme
substrate (See for example, Carmen, A. A., Rundlett, S. E.,
Grunstein, M. J. Biol. Chem. (1996) 271, 15837-15844, the contents
of which is incorporated herein by reference in its entirety). In
this procedure the hydroxamic acid compounds of the present
invention, in an appropriate solvent such as dimethylsulfoxide
DMSO, are pre-incubated with recombinant HDACl enzyme for 30
minutes at 4.degree. C. in buffer containing 40 mM Tris-Cl, pH=7.6,
20 mM EDTA and 50% glycerol. At 37.degree. C., the
[.sup.3H]-labeled acetylated histones are added and incubated for
about 10 minutes. The released [.sup.3H]-acetic acid is then
extracted and quantified by scintillation count.
[0118] All patents, patent applications, and published references
cited herein are hereby incorporated by reference in their
entirety. While this invention has been particularly illustrated
and described with references to particular examples of preferred
embodiments thereof, it will be understood by those skilled in the
art that various changes in form and details may be made therein
without departing from the scope and spirit of the invention
encompassed by the appended claims.
* * * * *